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179篇 您的检索式:作者名="Yang Zhiguo"
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1Towards 6G wireless communication networks:vision,enabling technologies,and new paradigm shifts显示文摘The fifth generation(5G)wireless communication networks are being deployed worldwide from 2020 and more capabilities are in the process of being standardized,such as mass connectivity,ultra-reliability,and guaranteed low latency.However,5G will not meet all requirements of the future in 2030 and beyond,and sixth generation(6G)wireless communication networks are expected to provide global coverage,enhanced spectral/energy/cost efficiency,better intelligence level and security,etc.To meet these requirements,6G networks will rely on new enabling technologies,i.e.,air interface and transmission technologies and novel network architecture,such as waveform design,multiple access,channel coding schemes,multi-antenna technologies,network slicing,cell-free architecture,and cloud/fog/edge computing.Our vision on 6G is that it will have four new paradigm shifts.First,to satisfy the requirement of global coverage,6G will not be limited to terrestrial communication networks,which will need to be complemented with non-terrestrial networks such as satellite and unmanned aerial vehicle(UAV)communication networks,thus achieving a space-airground-sea integrated communication network.Second,all spectra will be fully explored to further increase data rates and connection density,including the sub-6GHz,millimeter wave(mmWave),terahertz(THz),and optical frequency bands.Third,facing the big datasets generated by the use of extremely heterogeneous networks,diverse communication scenarios,large numbers of antennas,wide bandwidths,and new service requirements,6G networks will enable a new range of smart applications with the aid of artificial intelligence(AI)and big data technologies.Fourth,network security will have to be strengthened when developing 6G networks.This article provides a comprehensive survey of recent advances and future trends in these four aspects.Clearly,6G with additional technical requirements beyond those of 5G will enable faster and further communications to the extent that the boundary between physical and cyber worlds disappears.Xiaohu YOU Cheng-Xiang WANG Jie HUANG Xiqi GAO Zaichen ZHANG Mao WANG Yongming HUANG Chuan ZHANG Yanxiang JIANG Jiaheng WANG Min ZHU Bin SHENG Dongming WANG Zhiwen PAN Pengcheng ZHU Yang YANG Zening LIU Ping ZHANG Xiaofeng TAO Shaoqian LI Zhi CHEN Xinying MA Chih-Lin I Shuangfeng HAN Ke LI Chengkang PAN Zhimin ZHENG Lajos HANZO Xuemin(Sherman)SHEN Yingjie Jay GUO Zhiguo DING Harald HAAS Wen TONG Peiying ZHU Ganghua YANG Jun WANG Erik GLARSSON Hien Quoc NGO Wei HONG Haiming WANG Debin HOU Jixin CHEN Zhe CHEN Zhangcheng HAO Geoffrey Ye LI Rahim TAFAZOLLI Yue GAO HVincent POOR Gerhard P.FETTWEIS Ying-Chang LIANG 2021Science China(Information Sciences)2021,64,1:122
2Glacial distribution and mass balance in the Yarlung Zangbo River and its influence on lakes显示文摘Glaciers in the Yarlung Zangbo River witness severe glacial retreat nowadays,which gives important influence on lake processes in the region.We have studied glacial distribution,glacial mass balance and found large deficit in glacial mass and its impact in the region.Our study also integrated the variation in glacial-fed lakes of the Nam Co and Ranwu Lake,and presented an initial assessment of the impact of glacial mass balance on lakes.The study has shown a significant contribution of glacial melting to recent lake expansion and lake level rising.YAO TanDong LI ZhiGuo YANG Wei GUO XueJun ZHU LiPing KANG ShiChang WU YanHong YU WuSheng 2010Chinese Science Bulletin2010,55,20:34
3Mid-Late Quaternary loess-paleosol sequence in Lantian's Yushan,China:An environmental magnetism approach and its paleoclimatic significance显示文摘The application of rock magnetism methods to investigating the variations of magnetic minerals in the sediments is an important approach to the reestablishment of paleoclimate evolution. Thus we performed fine magnetic measurements on the loess-paleosol sequence (from L15 upwards to S5, in which L is short for Loess, S is short for Paleosol, the same hereinafter) of Yushan strati-graphic section, which is on the southeastern margin of Chinese Loess Plateau, in Lantian County of China's Shaanxi Province, and the thickness of which is ca. 40 m. Our study shows that the primary magnetic carriers of loess and paleosol in this section are magnetite, maghemite, hematite and goethite. Thermomagnetic analyses on the samples of representative horizons show that the higher pedogenesis degree of the sediments, the smaller variations of magnetization there will be before and after heating, probably related to the pedogenic alteration of loess sediments. Analyses of several magnetic parameters show a significant discrepancy between the paleoclimatic conditions recorded in the strata from the loess unit L15 upward to the paleosol unit S5 in the study area and those recorded in the relative strata of other sections on the Chinese Loess Plateau, and those recorded in marine sediments, indicating the great impact of regional geological background. Similarly, the rapid and intensive change recorded in the segment from L15 to S9-1, and the significant difference between the paleoclimate evolutions of the two periods before and after the change (from L15 to S9-1, and from L9 to the base of S6) indicate the strong alteration of magnetic carriers in the study area as a result of the alternations of summer and winter monsoons in East Asia.WU Yi ZHU ZhaoYu RAO ZhiGuo QIU ShiFan YANG Tian 2010Chinese Science Bulletin2010,55,26:10
4Rehabilitation and Sustainable Use Pattern of Rocky-desertified Land in Southwest China’s Poverty-stricken Karst Mountainous Areas——A Case Study in Benggu Township, Xichou County, Yunnan, China显示文摘The rocky desert in a karst area directly causes the lack of soil, water and forest, hence leading to the poverty there. In 1990, the villagers from the Muzhe Village in Benggu Township, Xichou County, Yunnan declared a war against rocky desert in an attempt to ask the fields for more yields. They invented a distinctive land rehabilitation and sustainable use pattern called “transforming heavenand earth” that had been practiced in Southwest China’s karst areas. The key mechanism of the pattern was to develop terraced fields with well conserved soil, water and fertility by exploding rocks in the fields, building stone walls, gathering more soil, and improving soil quality and productivity for the fields in combination with building of irrigation facilities and roads, as well as with forestation and agriculture structure adjustment. The purpose of the pattern was to alleviate poverty in the karst areas by improving soil productivity and promoting agriculturaldevelopment. A typical area was studied with the help of Participatory Rural Appraisal (PRA) and the pattern was carried out there for fifteen years, have produced excellent ecological benefits and good economic benefits. Its application in the area approved that it was a sustainable land use pattern for rocky desert areas.YANG Zisheng LIU Yansui BAO Guangjing LI Zhiguo HE Yimei 2006Journal of Mountain Science2006,3,3:10
5Further results on existence-uniqueness for stochastic functional differential equations显示文摘The aim of this paper is to develop some basic theories of stochastic functional differential equations (SFDEs) under the local Lipschitz condition in continuous functions space C. Firstly, we establish a global existence-uniqueness lemma for the SFDEs under the global Lipschitz condition in C without the linear growth condition. Then, under the local Lipschitz condition in C, we show that the non-continuable solution of SFDEs still exists if the drift coefficient and diffusion coefficient are square-integrable with respect to t when the state variable equals zero. And the solution of the considered equation must either explode at the end of the maximum existing interval or exist globally. Furthermore, some more general sufficient conditions for the global existence-uniqueness are obtained. Our conditions obtained in this paper are much weaker than some existing results. For example, we need neither the linear growth condition nor the continuous condition on the time t. Two examples are provided to show the effectiveness of the theoretical results.XU DaoYi WANG XiaoHu YANG ZhiGuo 2013Science China Mathematics2013,56,6:8
6Preliminary analysis of spatiotemporal pattern of global land surface water显示文摘Land surface water(LSW) is one of the most important resources for human survival and development, and it is also a main component of global water recycling. A full understanding of the spatial distribution of land surface water and a continuous measuring of its dynamics can support to diagnose the global ecosystem and environment. Based on the Global Land 30-water 2000 and Global Land 30-water 2010 products, this research analyzed the spatial distribution pattern and temporal fluctuation of land surface water under scale-levels of global, latitude and longitude, continents, and climate zones. The Global Land 30-water products were corrected the temporal inconsistency of original remotely sensed data using MODIS time-series data, and then calculated the indices such as water area, water ration and coefficient of spatial variation for further analysis. Results show that total water area of land surface is about 3.68 million km2(2010), and occupies 2.73% of land area. The spatial distribution of land surface water is extremely uneven and is gathered mainly in mid- to high-latitude area of the Northern Hemisphere and tropic area. The comparison of water ratio between 2000 and 2010 indicates the overall fluctuation is small but spatially differentiated. The Global Land 30-water products and the statistics provided the fundamental information for analyzing the spatial distribution pattern and temporal fluctuation of land surface water and diagnosing the global ecosystem and environment.CAO Xin CHEN Jun CHEN LiJun LIAO AnPing SUN FangDi LI Yang LI Lei LIN ZhongHui PANG ZhiGuo CHEN Jin HE ChaoYing PENG Shu 2014Science China Earth Sciences2014,57,10:8
7Effect of N fertilization rate on soil alkalihydrolyzable N, subtending leaf N concentration,fiber yield, and quality of cotton显示文摘Soil alkali-hydrolyzable nitrogen, which is sensitive to N fertilization rate, is one of the indicators of soil nitrogen supplying capacity. Two field experiments were conducted in Dongtai(120°19″ E, 32°52″ N), Jiangsu, China in 2009 and Dafeng(120°28″ E, 33°12″ N), Jiangsu province, China in 2010. Six nitrogen rates(0, 150, 300, 375, 450, and 600 kg ha^(-1)) were used to study the effect of N fertilization rate on soil alkali-hydrolyzable nitrogen content(SAHNC), subtending leaf nitrogen concentration(SLNC), yield, and fiber quality. In both Dongtai and Dafeng experiment station, the highest yield(1709 kg ha^(-1)), best quality(fiber length 30.6 mm, fiber strength 31.6 c N tex^(-1), micronaire 4.82), and highest N agronomic efficiency(2.03 kg kg^(-1)) were achieved at the nitrogen fertilization rate of 375 kg ha^(-1). The dynamics of SAHNC and SLNC could be simulated with a cubic and an exponential function,respectively. The changes in SAHNC were consistent with the changes in SLNC. Optimal average rate(0.276 mg day^(-1)) and duration(51.8 days) of SAHNC rapid decline were similar to the values obtained at the nitrogen rate of 375 kg ha^(-1)at which cotton showed highest fiber yield, quality, and N agronomic efficiency. Thus, the levels and strategies of nitrogen fertilization can affect SAHNC dynamics. The N fertilization rate that optimizes soil alkali-hydrolyzable nitrogen content would optimize the subtending leaf nitrogen concentration and thereby increase the yield and quality of the cotton fiber.Binglin Chen Hongkun Yang Weichao Song Chunyu Liu Jiao Xu Wenqing Zhao Zhiguo Zhou 2016The Crop Journal2016,4,4:8
8Highly Efficient and Stable Hydrogen Production in All pH Range by Two-Dimensional Structured Metal-Doped Tungsten Semicarbides显示文摘Transition-metal-doped tungsten semicarbide nanosheets(M-doped W_(2)C NSs,M=Fe,Co,and Ni)have been synthesized through carburization of the mixture of tungsten trioxide,polyvinylpyrrolidone,and metal dopant.Te nanosheets grow directly on the W mesh and have the lateral dimension of several hundreds of nm to a few�m with a thickness of few tens nm.It is demonstrated that the M-doped W_(2)C NSs exhibit superior electrocatalytic activity for hydrogen evolution reaction(HER).Impressively,the Nidoped W_(2)C NSs(2 at%Ni)with the optimized HER activity show extremely low onset overpotentials of 4,9,and 19 mV and modest Tafel slopes of 39,51,and 87 mV dec−1 in acidic(pH=0),neutral(pH=7.2),and basic(pH=14)solutions,respectively,which is close to the commercial Pt/C catalyst.Density functional theory(DFT)calculations also demonstrate that the Gibbs free energy for H adsorption of Ni-W_(2)C is much closer to the optimal valueG_(H∗)=-0.073 eV as compared to-0.16 eV of W_(2)C.Furthermore,nearly 100%Faradaic efciency and long-term stability are obtained in those environments.Tis realization of highly tolerant metal semicarbide catalyst performing on par with commercial Pt/C in all range of pH ofers a key step towards industrially electrochemical water splitting.Edison H.Ang Khang N.Dinh Xiaoli Sun Ying Huang Jun Yang Zhili Dong Xiaochen Dong Wei Huang Zhiguo Wang Hua Zhang Qingyu Yan 2019Research2019,,1:7
9Advances and prospects in biomimetic multilayered scaffolds for articular cartilage regeneration显示文摘Due to the sophisticated hierarchical structure and limited reparability of articular cartilage(AC),the ideal regeneration of AC defects has been a major challenge in the field of regenerative medicine.As defects progress,they often extend from the cartilage layer to the subchondral bone and ultimately lead to osteoarthritis.Tissue engineering techniques bring new hope for AC regeneration.To meet the regenerative requirements of the heterogeneous and layered structure of native AC tissue,a substantial number of multilayered biomimetic scaffolds have been studied.Ideal multilayered scaffolds should generate zone-specific functional tissue similar to native AC tissue.This review focuses on the current status of multilayered scaffolds developed for AC defect repair,including design strategies based on the degree of defect severity and the zone-specific characteristics of AC tissue,the selection and composition of biomaterials,and techniques for design and manufacturing.The challenges and future perspectives of biomimetic multilayered scaffold strategies for AC regeneration are also discussed.Liwei Fu Zhen Yang Cangjian Gao Hao Li Zhiguo Yuan Fuxin Wang Xiang Sui Shuyun Liu Quanyi Guo 2020Regenerative Biomaterials2020,7,6:7
10Acetyl salicylic acid attenuates cardiac hypertrophy through Wnt signaling显示文摘室的肥大是心血管的疾病的事件的一个强大、独立的预言者。低剂量的乙酰水杨酸酸(阿司匹林) 的脉管的性质通过血小板 cyclooxygenase 的不可逆的抑制提供心血管的好处 1;然而,可能的 anti-hypertrophic 性质和阿司匹林的潜在的机制没详细被调查。在这研究,健康野类型的雄的老鼠随机被划分成三个组并且使遭到了到横向的大动脉的收缩(TAC ) 或假冒的操作。操作 TAC 的老鼠与低剂量的阿司匹林的人的等价物被对待(10 mg 吗?Samuel Chege Gitau Xuelian Li Dandan Zhao Zhenfeng Guo Haihai Liang Ming Qian Lifang Lv Tianshi Li Bozhi Xu Zhiguo Wang Yong Zhang Chaoqian Xu Yanjie Lu Zhiming Du Hongli Shan Baofeng Yang 2015Frontiers of Medicine2015,9,4:6
11Chemical characteristics and source apportionment of PM_(2.5) in a petrochemical city: Implications for primary and secondary carbonaceous component显示文摘To study the pollution features and underlying mechanism of PM_(2.5) in Luoyang, a typical developing urban site in the central plain of China, 303 PM_(2.5) samples were collected from April 16 to December 29, 2015 to analyze the elements, water soluble inorganic ions, organic carbon and elemental carbon. The annual mean concentration of PM_(2.5) was 142.3 μg/m^(3), and 75% of the daily PM_(2.5) concentrations exceeded the 75 μg/m^(3). The secondary inorganic ions, organic matter and mineral dust were the most abundant species, accounting for 39.6%, 19.2% and 9.3% of the total mass concentration, respectively. But the major chemical components showed clear seasonal dependence. SO_(4)^(2-) was most abundant specie in spring and summer, which related to intensive photochemical reaction under high O_3 concentration. In contrast, the secondary organic carbon and ammonium while primary organic carbon and ammonium significantly contributed to haze formation in autumn and winter, respectively. This indicated that the collaboration effect of secondary inorganic aerosols and carbonaceous matters result in heavy haze in autumn and winter. Six main sources were identified by positive matrix factorization model: industrial emission, combustion sources, traffic emission, mineral dust, oil combustion and secondary sulfate, with the annual contribution of 24%, 20%, 24%, 4%, 5% and 23%, respectively. The potential source contribution function analysis pointed that the contribution of the local and short-range regional transportation had significant impact. This result highlighted that local primary carbonaceous and precursor of secondary carbonaceous mitigation would be key to reduce PM_(2.5) and O_3 during heavy haze episodes in winter and autumn.Guangxuan Yan Puzhen Zhang Jie Yang Jingwen Zhang Guifen Zhu Zhiguo Cao Jing Fan Zirui Liu Yuesi Wang 2021Journal of Environmental Sciences2021,33,5:6
12Reversible 3D optical data storage and information encryption in photo-modulated transparent glass medium显示文摘Transparent glass has been identified as a vital medium for three-dimensional(3D)optical information storage and multi-level encryption.However,it has remained a challenge for directly writing 3D patterning inside a transparent glass using semiconductor blue laser instead of high-cost femtosecond laser.Here,we demonstrate that rare earth ions doped transparent glass can be used as 3D optical information storage and data encryption medium based on their reversible transmittance and photoluminescence manipulation.The color of tungsten phosphate glass doped with rare earth ions change reversibly from light yellow to blue upon alternating 473 nm laser illumination and temperature stimulation,resulting in the reversible luminescence modulation.The information data could be repeatedly written and erased in arbitrary 3D space of transparent glass,not only showing the ability of the excellent reproducibility and storage capacity,but also opening opportunities in information security.The present work expands the application fields of luminescent glass,and it is conducive to develop a novel 3D data storage and information encryption media.Zhen Hu Xiongjian Huang Zhengwen Yang Jianbei Qiu Zhiguo Song Junying Zhang Guoping Dong 2021Light(Science & Applications)2021,10,8:6
13Determination of thermal expansion coefficients for unidirectional fiber-reinforced composites显示文摘In the present work, the coefficients of thermal expansion(CTEs) of unidirectional(UD)fiber-reinforced composites are studied. First, an attempt is made to propose a model to predict both longitudinal and transverse CTEs of UD composites by means of thermo-elastic mechanics analysis. The proposed model is supposed to be a concentric cylinder with a transversely isotropic fiber embedded in an isotropic matrix, and it is subjected to a uniform temperature change. Then a concise and explicit formula is offered for each CTE. Finally, some finite element(FE) models are created by a finite element program MSC. Patran according to different material systems and fiber volume fractions. In addition, the available experimental data and results of other analytical solutions of CTEs are presented. Comparisons are made among the results of the cylinder model,the finite element method(FEM), experiments, and other solutions, which show that the predicted CTEs by the new model are in good agreement with the experimental data. In particular, transverse CTEs generally offer better agreements than those predicted by most of other solutions.Ran Zhiguo Yan Ying Li Jianfeng Qi Zhongxing Yang Lei 2014Chinese Journal of Aeronautics2014,27,5:5
14Reactive mesoporous silica nanoparticles loaded with limonene for improving physical and mental health of mice at simulated microgravity condition显示文摘Astronauts are under high stress for a long time because of the microgravity condition,which leads to anxiety,affects their learning and memory abilities,and seriously impairs the health of astronauts.Aromatherapy can improve the physical and mental health of astronauts in a way that moisturizes them softly and silently.However,the strong volatility of fragrances and inconvenience of aroma treatment greatly limit their application in the field of spaceflight.In this study,reactive mesoporous silica nanoparticles were prepared to encapsulate and slowly release limonene.The limonene loaded nanoparticles were named limonene@mesoporous silica nanoparticles-cyanuric chloride(LE@MSNs-CYC).LE@MSNs-CYC were then applied to wallpaper to improve the convenience of aromatherapy.LE@MSNs-CYC could chemically react with the wallpaper,thus firmly adsorbed on the wallpaper.In the following,the mice were treated with hindlimb unloading(HU)to simulate a microgravity environment.The results showed that 28-day HU led to an increase in the level of anxiety and declines in learning,memory,and physical health in mice.LE@MSNs-CYC showed significant relief effects on anxiety,learning,memory,and physical health of HU treated mice.Subsequently,the molecular mechanisms were explored by hypothalamic-pituitary-adrenal axis related hormones,immune-related cytokines,learning,and memory-related neurotransmitters and proteins.Zhiguo Lu Jianze Wang Lina Qu Guanghan Kan Tianlu Zhang Jie Shen Yan Li Jun Yang Yunwei Niu Zuobing Xiao Yinghui Li Xin Zhang 2020Bioactive Materials2020,5,4:5
15Bevacizumab biosimilar LY01008 compared with bevacizumab(Avastin)as first-line treatment for Chinese patients with unresectable,metastatic,or recurrent non-squamous non-small-cell lung cancer:A multicenter,randomized,double-blinded,phase Ⅲ trial显示文摘Background:Previous studies have demonstrated the preclinical pharmacological and toxicological consistency,and clinical pharmacokinetic equivalence of bevacizumab biosimilar LY01008 with reference bevacizumab(Avastin).This randomized controlled trial aimed to compare the efficacy and safety of LY01008 with Avastin in first-line treatment of Chinese patients with advanced or recurrent non-squamous non-small cell lung cancer(NSCLC).Methods:StageⅢB-ⅣNSCLC patients with evaluable lesions,good physical status,and adequate organ functions from 67 centers across China were randomized in a ratio of 1:1 to receive LY01008 or Avastin 15 mg/kg intravenously in combination with paclitaxel/carboplatin(combined treatment)for 4-6 cycles,followed by maintenance monotherapy with LY01008 until disease progression,intolerable toxicity,or death.The primary endpoint was objective response rate(ORR)in accordance with Response Evaluation Criteria in Solid Tumors(RECIST)version 1.1 confirmed by independent radiological review committees(IRRC).Secondary endpoints included disease control rate(DCR),duration of response(DoR),progression-free survival(PFS),overall survival(OS),and safety.This study was registered in Clinical Trials.gov(NCT03533127).Results:Between December 15^(th),2017,and May 15^(th),2019,a total of 649 patients were randomized to the LY01008(n=324)or Avastin(n=325)group.As of September 25th,2019 for primary endpoint analysis,589 patients received ORR evaluation,with a median number of combined treatment cycles of 5(range 1-6)andmedian duration of treatment of 3.0(range 0.0-5.1)months.ORRof responseevaluable patients in the LY01008 and Avastin groups were 48.5% and 53.0%,respectively.The stratified ORR ratio was 0.91(90%CI 0.80-1.04,within the prespecified equivalence margin of 0.75-1.33).Up to May 15^(th),2020,with a median follow-up of 13.6(range 0.8-28.4)months,no notable differences in DCR,median DoR,median PFS,median OS,and 1-year OS rate were observed between the LY01008 and Avastin groups.There were no clinically meaningful differences in safety and immunogenicity across treatment groups.Conclusions:LY01008 demonstrated similarity to Avastin in terms of efficacy and safety in Chinese patients with advanced or recurrent non-squamous NSCLC.LY01008 combined with paclitaxel/carboplatin is expected to become a new treatment option for unresectable,metastatic,LY01008 and Avastin groups.There were no clinically meaningful differences in safety and immunogenicity across treatment groups.Conclusions:LY01008 demonstrated similarity to Avastin in terms of efficacy and safety in Chinese patients with advanced or recurrent non-squamous NSCLC.LY01008 combined with paclitaxel/carboplatin is expected to become a new treatment option for unresectable,metastatic,or recurrent non-squamous NSCLC patients in the first-line setting.Yuankai Shi Kaijian Lei Yuming Jia Bingqiang Ni Zhiyong He Minghong Bi Xicheng Wang Jianhua Shi Ming Zhou Qian Sun Guolei Wang Dongji Chen Yongqian Shu Lianke Liu Zhongliang Guo Yong Liu Junquan Yang Ke Wang Ke Xiao LinWu Tienan Yi Debin Sun Mafei Kang Tianjiang Ma Yimin Mao Jinsheng Shi Tiegang Tang Yan Wang Puyuan Xing Dongqing Lv Wangjun Liao Zhiguo Luo Bin Wang Xiaohong Wu Xiaoli Zhu Shuhua Han Qisen Guo Rongyu Liu Zhiwei Lu Jianyong Zhang Jian Fang Changlu Hu Yinghua Ji Guolong Liu Hong Lu Dedong Wu Junhong Zhang Shuyang Zhu Zheng Liu Wensheng Qiu Feng Ye Yan Yu Yanqiu Zhao Qinhong Zheng Jun Chen Zhanyu Pan Yiping Zhang Wenjuan Lian Bo Jiang Bo Qiu Guojun Zhang Hua Zhang Yanju Chen Yuan Chen Hongbing Duan Manxiang Li Shengming Liu Lijun Ma Hongming Pan Xia Yuan Xueli Yuan Yulong Zheng Emei Gao Li Zhao Shumin Wang Can Wu 2021Cancer Communications2021,41,9:5
16Microstructure and wear resistance of highchromium cast iron containing niobium显示文摘In the paper, the effect of niobium addition on the microstructure, mechanical properties and wear resistance of high chromium cast iron has been studied. The results show that the microstructure of the heattreated alloys is composed of M7C3 and M23C6 types primary carbide, eutectic carbide, secondary carbide and a matrix of martensite and retained austenite. NbC particles appear both inside and on the edge of the primary carbides. The hardness of the studied alloys maintains around 66 HRC, not significantly affected by the Nb content within the selected range of 0.48%-0.74%. The impact toughness of the alloys increases with increasing niobium content. The wear resistance of the specimens presents little variation in spite of the increase of Nb content under a light load of 40 N. However, when heavier loads of 70 and 100 N are applied, the wear resistance increases with increasing Nb content.Zhang Zhiguo Yang Chengkai Zhang Peng Li Wei 2014China Foundry2014,11,3:4
17Derivation of Cloud-Free-Region Atmospheric Motion Vectors from FY-2E Thermal Infrared Imagery显示文摘The operational cloud-motion tracking technique fails to retrieve atmospheric motion vectors(AMVs) in areas lacking cloud; and while water vapor shown in water vapor imagery can be used, the heights assigned to the retrieved AMVs are mostly in the upper troposphere. As the noise-equivalent temperature difference(NEd T) performance of FY-2E split window(10.3–11.5 μm, 11.6–12.8 μm) channels has been improved, the weak signals representing the spatial texture of water vapor and aerosols in cloud-free areas can be strengthened with algorithms based on the difference principle, and applied in calculating AMVs in the lower troposphere. This paper is a preliminary summary for this purpose, in which the principles and algorithm schemes for the temporal difference, split window difference and second-order difference(SD) methods are introduced. Results from simulation and cases experiments are reported in order to verify and evaluate the methods, based on comparison among retrievals and the 'truth'. The results show that all three algorithms, though not perfect in some cases,generally work well. Moreover, the SD method appears to be the best in suppressing the surface temperature influence and clarifying the spatial texture of water vapor and aerosols. The accuracy with respect to NCEP 800 h Pa reanalysis data was found to be acceptable, as compared with the accuracy of the cloud motion vectors.Zhenhui WANG Xinxiu SUI Qing ZHANG Lu YANG Hang ZHAO Min TANG Yizhe ZHAN Zhiguo ZHANG 2017Advances in Atmospheric Sciences2017,34,2:4
18Hybridization of metal–organic framework and monodisperse spherical silica for chromatographic separation of xylene isomers显示文摘Metal–organic frameworks(MOFs) packed in the column have been a promising candidate as the stationary phase for high performance liquid chromatography(HPLC). However, the direct packing of irregular MOF powder could raise some problems like high back pressure and low column efficiency in the HPLC separation. In this work, UiO-66 capable of separating xylenes was supported effectively on the surface of the monodisperse spherical silica microspheres by one-pot method. The hybridization of Ui O-66 and silica microspheres(termed UiO-66@SiO2 shell–core composite) was prepared by stirring the suspension of the precursors of Ui O-66 and\\COOH terminated silica in the N,N-dimethylformamide with heating. The shell–core composite material UiO66@SiO2 was characterized by SEM, TEM, PXRD and FTIR. Then, it was used as a packing material for the chromatographic separation of xylene isomers. Xylene isomers including o-xylene, m-xylene and p-xylene were efficiently separated on the column with high resolution and good reproducibility. Moreover, the Ui O-66@SiO2 shell–core composites packed column still remained reverse shape selectivity as Ui O-66 possessed, and the retention of xylenes was probably ascribed to the hydrophobic effect between analytes and the aromatic rings of the Ui O-66 shell. The Ui O-66@SiO2 shell–core composites obtained in this study have some potential for the separation of structural isomers in HPLC.Bixuan Gao Minhui Huang Zhiguo Zhang Qiwei Yang Baogen Su Yiwen Yang Qilong Ren Zongbi Bao 2019Chinese Journal of Chemical Engineering2019,27,4:4
19Efficient genetic transformation and CRISPR/Cas9-mediated genome editing of watermelon assisted by genes encoding developmental regulators显示文摘Cucurbitaceae is an important family of flowering plants containing multiple species of important food plants,such as melons,cucumbers,squashes,and pumpkins.However,a highly efficient genetic transformation system has not been established for most of these species(Nanasato and Tabei,2020).Watermelon(Citrullus lanatus),an economically important and globally cultivated fruit crop,is a model species for fruit quality research due to its rich diversity of fruit size,shape,flavor,aroma,texture.Wenbo PAN Zhentao CHENG Zhiguo HAN Hong YANG Wanggen ZHANG Huawei ZHANG 2022Journal of Zhejiang University-Science B(Biomedicine & Biotechnology)2022,23,4:4
20Solvent engineering towards scalable fabrication of high-quality perovskite films for efficient solar modules显示文摘Over the last decade,remarkable progress has been made in metal halide perovskite solar cells(PSCs),which have been a focus of emerging photovoltaic techniques and show great potential for commercialization.However,the upscaling of small-area PSCs to large-area solar modules to meet the demands of practical applications remains a significant challenge.The scalable production of high-quality perovskite films by a simple,reproducible process is crucial for resolving this issue.Furthermore,the crystallization behavior in the solution-processed fabrication of perovskite films can be strongly influenced by the physicochemical properties of the precursor inks,which are significantly affected by the employed solvents and their interactions with the solutes.Thus,a comprehensive understanding of solvent engineering for fabricating perovskite films over large areas is urgently required.In this paper,we first analyze the role of solvents in the solution-processed fabrication of large-area perovskite films based on the classical crystal nucleation and growth mechanism.Recent efforts in solvent engineering to improve the quality of perovskite films for solar modules are discussed.Finally,the basic principles and future challenges of solvent system design for scalable fabrication of high-quality perovskite films for efficient solar modules are proposed.Zhaoyi Jiang Binkai Wang Wenjun Zhang Zhichun Yang Mengjie Li Fumeng Ren Tahir Imran Zhenxing Sun Shasha Zhang Yiqiang Zhang Zhiguo Zhao Zonghao Liu Wei Chen 2023Journal of Energy Chemistry2023,,5:4
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